Guillaume asked me why wines in magnums, double magnums and in large formats in general seem to taste and age better.
In my experience, it is true that at least in magnums, wine keeps more fruit and ages better. The reason is simple: there is most likely less oxidation due to the exchange of oxygen passing through the cork (?) but especially contact with the cork (being almost the same size as a 75 cl bottle) is divided by 2 and even more for double magnums and Imperials.
Corks are responsible for giving a sort of oxidation taste, except for glass corks (which are now being tested).
Another important factor is the temperature of storage. The colder it is (14 to 15° C or 57 to 59° F), the slower the wine ages (which explains why the oxidation is slower when an open bottle of red wine is kept in the refrigerator). This is reason why wines tasted in the winery taste better for the cellars are often cold.
Yesterday we had a heat wave: more than 35° C (95° F) in the shade.